The present invention relates to an automatic nailer system particularly, but not exclusively, for use in the joinery industry.
In manufacturing items of joinery such as doors and cupboards, it is common practice nowadays to provide a molded plastic trim to cover over the joints between the sections of the item, or for general decoration of finished chip-board furniture. For instance, a door may comprise a central chipboard panel located in grooves in a surrounding softwood frame. To cover the grooves and the joints between the panel and frame, a generally triangular molded plastic trim is fitted onto the door at the periphery of the panel.
In one method of fitting the trim, a number of metal ferrules are nailed, at predetermined spacings, onto the panel and the frame. A typical prior art ferrule is shown in FIG. 1 of the accompanying drawings to which reference is now made. Each ferrule 1 is generally cylindrical and has a step 2 at approximately its midpoint. The thicker portion 3 tapers from the step 2 towards the end. Each ferrule is fixed by a nail passing through hole 6 so that the end of the thinner portion 4 of the ferrule abuts the panel or frame, thereby forming a groove comprising the panel or frame, the cylindrical side of the thinner portion 4 of the ferrule 1 and the bottom of the step 2. A flange provided on the inside of the trim is clipped into the groove to retain the trim in place.
In order to ensure that the trim fits properly on the door, it is necessary to ensure that the ferrules are correctly aligned with one another. At present, this is achieved by an operator firstly manually marking out, for instance with a bradawl, the position at which each ferrule is to be located and then manually hammering a nail through the ferrule into the marked position. As the nails and, in particular, the ferrules are small (each ferrule is generally about 4 mm long and at maximum 5 mm in diameter) this is a delicate task and therefore cannot be carried out quickly even by a skilled worker. Moreover, as any given door will usually have a minimum of twenty-four ferrules, the time taken to fit the ferrules properly on the door will be considerable.
Moreover, since the nails are driven manually, they are not always accurately aligned with the markings. Thus, when the trim is fitted, it often is not straight, and a further operation needs to be carried out to bend the nails so that the trim can be located properly on the door.
This method of fitting trim is therefore disadvantageous in that it is labor intensive, slow and not always accurate. However, it has the advantage that the trim is positively and permanently located on the door.
There has therefore been a trend in recent years to the use of double-sided adhesive tape for locating the trim on a door. This speeds up the process for fitting the trim, since it is only necessary to strip the protective cover from the adhesive tape and lay a length of trim adjacent a template. This also gives a more accurate location of the trim. However, this process is disadvantageous because it increases substantially the cost of the trim, since the trim is solid and has on it the double-sided adhesive tape, and does not lead to a permanent fixture of the trim, since the adhesive effect of the tape can be readily overcome by adverse atmospheric conditions, such as bright sunlight, aging or physical force.
Therefore, at present, there is not a fully satisfactory method for attaching trim to a door or similar item of joinery.
There are presently commercially available a number of automatic nailers, such as those supplied by Spot Nails Limited of Cardiff, Wales, United Kingdom. These nailers work in a similar fashion to stapling machines and comprise a track having an elongate opening along which a strip of nails is urged by a spring bias, and a piston driven hammer which drives the end one of the strip of nails into a substrate. The nails are held in the form of a strip either by a flexible lacquer coating (similar to the coating used to hold a strip of staples together) for small nails with a small or no head, or by a flexible strip of adhesive paper or plastic for larger nails with a substantial, generally T-shaped head.
It has not hitherto been possible to use an automatic nailer to fix ferrules to door frames or panels since it has not been possible to align the ferrule and the nail sufficiently well to ensure that the ferrule will correctly receive the nail as it is being hammered into the substrate. This could lead to damage to the ferrule, the automatic nailer and/or the substrate. Moreover, with the larger nails, the paper or plastic strip is driven with the nail and may interfere with the correct orientation of the ferrule on the substrate.
The present invention enables ferrules to be fixed onto an item of joinery automatically, thereby overcoming at least in part the problems of the present manual methods and of the inability to use automatic nailers for this purpose.